1. Field of the Invention
The present invention relates to game apparatus and methods, and in particular, to techniques responsive to a moving object propelled by a player toward a backstop.
2. Description of Related Art
Various means have been explored to measure speed and direction of a golf ball struck in a confined area. Many devices infer the ball trajectory information without the ball actually being set into flight. Several prior art devices utilize tethered balls and axle rotational speed or force measurements to provide estimates of the carry distance and/or direction. This target ball is often lighter and does not leave the tee unhindered, resulting in a different xe2x80x9cfeelxe2x80x9d for the golfer. Also, a club swung too high can result in damage to the club as the head may become entangled in the tether.
Other devices use magnetic or optical devices to measure the club head speed and orientation. There is a need to add a magnetic strip or reflector to the club head with these devices. Another disadvantage is that the actual ball flight is inferred, not measured. A missed ball can indicate a xe2x80x9cgoodxe2x80x9d drive in some implementations.
In U.S. Pat. No.5,826,874 magnetic sensors determine the path of a club head that is fitted with a magnet. Measurements are difficult over these short distances and at these high speeds. Moreover, this system provides only a rough estimate, since the trajectory of the club head does not unequivocally determine the flight path of the ball.
Most commercial simulation systems use infrared (IR), radar or optical planes to measure the ball trajectory, but these systems are cost prohibitive for personal use.
Several prior art devices exist for measuring impact location using grid wires or optical detectors. These devices require a large number of detectors and wires, which are costly.
Other devices employ a small number of linear displacement sensors on a net. Timing measurements along with deflection magnitudes provide the speed and direction information. These sensors are relatively costly and analog signal processing is required.
In U.S. Pat. No. 5,779,241 a number of cords are arranged in a grid within a net. The ends of each of the cords are wound on spring-biased reels inside sensors designed to respond to the linear extension of the cords, as caused by impact by a golf ball. The intersection of cords exhibiting the highest extension determines the point of impact on the net. Velocity can be estimated by analyzing the signals produced by the sensors. This system is relatively complex in that it requires a large number of sensors and the analysis of a correspondingly large number of signals.
In U.S. Pat. No. 5,820,496 the four corners of a net are supported by spring-biased cords. Four linear displacement sensors can measure motion of these cords, as caused by a ball impacting the net. It is difficult to accurately measure linear distances in this fashion. Also, these measurements are resolved by relatively elaborate mathematics, in order to determine the ball position and velocity at the net. Manipulating the outputs of these sensors is still too complicated.
Other devices use multiple microphones where the finite speed of sound allows impact location to be determined. The target must generate a sound upon impact, and thus is not suited for use with a conventional driving net.
Some golf simulation devices have been described which use an acoustic sensor to detect club impact as well as net switches to detect target impact time, but no means to use switch actuation times to determine impact location have been described.
In U.S. Pat. No. 4,086,630 a golf ball""s flight time to a net is determined by a sensor at the golf tee and sensors at the net. The net sensors are relatively sensitive and are connected together to provide a signal on a single line. Less sensitive zone sensors at the net provide a number of separate signals for determining if the ball has deviated from a straight-ahead path. The quantized zone signals are used to degrade the calculated distance, depending upon the amount of deviation from a straight-ahead path. This system is relatively complicated in that it requires a number of zone sensors for determining flight azimuth, together with other sensors at the net for determining flight time.
In U.S. Pat. No. 3,938,809 a counting device issues timing pulses between the time of impact of the ball with (1) the club head, as detected by an acoustic sensor, and (2) the net, as detected by a number of parallel switches. This system is unable to determine whether or not the flight of the ball is straight-ahead.
Once the speed and direction of a golf ball is determined, graphic simulation of play on a course can be provided with a computer. A popular package called Links by Access(trademark) exemplifies how play on a course is simulated.
The graphics are entertaining and realistic, but there is no true measurement of golfing ability, as speed and direction are input with a mouse-controlled timer.
The above mentioned U.S. Pat. No. 5,826,874 shows a device using magnetic sensors to determine head speed and direction. This device then implements software to mimic a mouse input to deliver the just measured parameters to the popular software package (Links by Access(trademark)). The electronics of this system are relatively complex, and the ball speed and direction are inferred just from the club head speed and orientation, without actually sending a ball in flight.
Accordingly, there is in need for an effective system that can determine flight characteristics of an object propelled by a player, with relatively simple and reliable detection techniques that will make the system available to consumers or other users.
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a game apparatus for determining flight characteristics of an object propelled by a player from a launch site toward a backstop. The apparatus includes a launch detector located at the launch site for producing a launch signal in response to launching of the object. Also included is a backstop sensing means located at the backstop and having at least one spaced pair of sensors for producing a pair of arrival signals in response to arrival of the object at the backstop. The apparatus also includes a processing means coupled to the launch detector and the backstop sensing means. The processing means can (a) determine the relative response times of the launch detector and the backstop sensing means, and (b) produce a characteristic signal as a function of the relative arrival times of the pair of arrival signals.
In accordance with another aspect of the invention a game method is provided for determining flight characteristics of an object propelled by a player from a launch site toward a backstop having a spaced pair of backstop sensors.
The method includes the step of producing a launch signal in response to launching of the object. Another step is determining the relative time between the launch signal and the response of at least one of the pair of backstop sensors. The method also includes the step of generating a characteristic signal as a function of the relative response times of the pair of backstop sensors.
Apparatus and methods of the foregoing type are described herein for determining the drive distance and direction of a golf ball (or other object) driven into a backstop or net. Club to ball impact detected by a preferred microphone starts the sequence. Ball to net (backstop) impact preferably actuates multiple sensors attached to the sides of the net. Preferably, the times from club impact to switch activation are analyzed to determine velocity, direction and carry distance, and to simulate a game of golf.
It is an object of the invention to provide a cost effective apparatus that can provide carry distance and directional information upon driving an object such as a golf ball into a backstop or net.
It is another object to provide a simple means, preferably employing switches at a net for determining time of flight from tee to net, and to correlate this to drive distance and to indicate direction; for example, hook/slice information derived by local signal processing circuitry with or without a computer.
In one embodiment a system captures time counted from tee impact to triggering of multiple net switches. The counts obtained thereby may be transferred to a personal computer for further data analysis and for displaying velocity, deviation angle from center, loft angle, and carry distance.
In one preferred embodiment, software will be employed for directly determining the times from tee to net switches, thus eliminating most of the required counter circuitry.
Preferably, the apparatus can determine the accuracy and speed of a putt with a ground-level backstop with two switches and an acoustic sensor.
A preferred computer can maintain information about ball position after each shot. The player""s object will then be to get to the green or hole in a minimum number of strokes. In one preferred embodiment, the measured parameters are transferred to commercially available software for simulation of play on a course.
A number of embodiments are anticipated utilizing switches on a golf net for velocity and direction feedback. The most cost effective embodiment of the present invention adds two switches to any golf net, a microphone near the tee, a small circuit comprising a comparator-triggered flip-flop and a 25-pin D connector, a software driver to acquire the timing information in the PC, software to calculate velocity, distance, direction and final ball position, and software to play a simple game from tee to green. Software to additionally interface with game simulation software such as the Links Access(trademark) simulation software can also be provided, along with the option to simulate putting.
Real time sensor acquisition may not, however, be desirable or possible with all PCs and all operating systems, and it is desired to offer some level of local processing as well as data transfer to a PC. Thus one preferred embodiment described below will include an arrangement with a discrete counter and latches, as well as putting apparatus and software for a simple golf game.